Radio synchronization configuration in different operation modes

ABSTRACT

Certain aspects of the present disclosure relate to methods and apparatus synchronization configuration in different operation modes using communications systems operating according to new radio (NR) technologies. For example, a method for wireless communications by a base station (BS) may include determining an operation mode of the BS, determining a transmission configuration of at least one of a one or more synchronization channels or a one or more synchronization signals based on the operation mode, and transmitting the one or more synchronization channels or the one or more synchronization signals based on the determined transmission configuration.

CLAIM OF PRIORITY UNDER 35 U.S.C. § 119

The present application for patent claims benefit of U.S. ProvisionalPatent Application Ser. No. 62/485,512, filed Apr. 14, 2017, U.S.Provisional Patent Application Ser. No. 62/489,017, filed Apr. 24, 2017,and U.S. Provisional Patent Application Ser. No. 62/569,120, filed Oct.6, 2017 assigned to the assignee hereof and hereby expresslyincorporated by reference herein.

BACKGROUND Field of the Disclosure

The present disclosure relates generally to communication systems, andmore particularly, to methods and apparatus for synchronizationconfiguration in different operation modes using communications systemsoperating according to new radio (NR) technologies.

Description of Related Art

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power). Examples of such multiple-access technologies includeLong Term Evolution (LTE) systems, code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

In some examples, a wireless multiple-access communication system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple communication devices, otherwise known asuser equipment (UEs). In LTE or LTE-A network, a set of one or more basestations may define an eNodeB (eNB). In other examples (e.g., in a nextgeneration or 5G network), a wireless multiple access communicationsystem may include a number of distributed units (DUs) (e.g., edge units(EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs),transmission reception points (TRPs), etc.) in communication with anumber of central units (CUs) (e.g., central nodes (CNs), access nodecontrollers (ANCs), etc.), where a set of one or more distributed units,in communication with a central unit, may define an access node (e.g., anew radio base station (NR BS), a new radio node-B (NR NB), a networknode, 5G NB, eNB, Next Generation Node B (gNB), etc.). A base station orDU may communicate with a set of UEs on downlink channels (e.g., fortransmissions from a base station or to a UE) and uplink channels (e.g.,for transmissions from a UE to a base station or distributed unit).

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example of an emergingtelecommunication standard is new radio (NR), for example, 5G radioaccess. NR is a set of enhancements to the LTE mobile standardpromulgated by Third Generation Partnership Project (3GPP). It isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingOFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink(UL) as well as support beamforming, multiple-input multiple-output(MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues toincrease, there exists a desire for further improvements in NRtechnology. Preferably, these improvements should be applicable to othermulti-access technologies and the telecommunication standards thatemploy these technologies.

BRIEF SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that include improvedcommunications between access points and stations in a wireless network.

Certain aspects provide a method for wireless communication by a basestation (BS). The method generally includes determining an operationmode of the BS, determining a transmission configuration of at least oneof a one or more synchronization channels or a one or moresynchronization signals based on the operation mode, and transmittingthe one or more synchronization channels or the one or moresynchronization signals based on the determined transmissionconfiguration.

Certain aspects provide a method for wireless communication by a userequipment (UE). The method generally includes determining a transmissionconfiguration, used by a base station (BS), to transmit at least one ofa one or more synchronization channels or a one or more synchronizationsignals based on an operation mode, and configuring the UE tocommunicate based on the transmission configuration.

Aspects generally include methods, apparatus, systems, computer readablemediums, and processing systems, as substantially described herein withreference to and as illustrated by the accompanying drawings.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects.

FIG. 1 is a block diagram conceptually illustrating an exampletelecommunications system, in accordance with certain aspects of thepresent disclosure.

FIG. 2 is a block diagram illustrating an example logical architectureof a distributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 3 is a diagram illustrating an example physical architecture of adistributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 4 is a block diagram conceptually illustrating a design of anexample BS and user equipment (UE), in accordance with certain aspectsof the present disclosure.

FIG. 5 is a diagram showing examples for implementing a communicationprotocol stack, in accordance with certain aspects of the presentdisclosure.

FIG. 6 illustrates an example of a DL-centric subframe, in accordancewith certain aspects of the present disclosure.

FIG. 7 illustrates an example of an UL-centric subframe, in accordancewith certain aspects of the present disclosure.

FIG. 8 illustrates example operations for a base station transmittingFDM data within synchronization signal (SS) bursts, in accordance withcertain aspects of the present disclosure.

FIG. 9 illustrates example operations for a user equipment (UE)receiving the SS bursts of FIG. 8, in accordance with certain aspects ofthe present disclosure.

FIG. 10 illustrates example operations for wireless communications by abase station (BS), in accordance with aspects of the present disclosure.

FIG. 11 illustrates example operations for wireless communications by auser equipment (UE), in accordance with aspects of the presentdisclosure.

FIG. 12 illustrates an example of synchronization transmissions, inaccordance with aspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements described in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processingsystems, and computer readable mediums for new radio (NR) (new radioaccess technology or 5G technology).

NR may support various wireless communication services, such as Enhancedmobile broadband (eMBB) targeting wide bandwidth (e.g. 80 MHz beyond),millimeter wave (mmW) targeting high carrier frequency (e.g. 27 GHz orbeyond), massive MTC (mMTC) targeting non-backward compatible MTCtechniques, and/or mission critical targeting ultra-reliable low latencycommunications (URLLC). These services may include latency andreliability requirements. These services may also have differenttransmission time intervals (TTI) to meet respective quality of service(QoS) requirements. In addition, these services may co-exist in the samesubframe.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in some other examples. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure described hereinmay be embodied by one or more elements of a claim. The word “exemplary”is used herein to mean “serving as an example, instance, orillustration.” Any aspect described herein as “exemplary” is notnecessarily to be construed as preferred or advantageous over otheraspects.

The techniques described herein may be used for various wirelesscommunication networks such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA andother networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA network may implement aradio technology such as Global System for Mobile Communications (GSM).An OFDMA network may implement a radio technology such as NR (e.g. 5GRA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA andE-UTRA are part of Universal Mobile Telecommunication System (UMTS). NRis an emerging wireless communications technology under development inconjunction with the 5G Technology Forum (5GTF). 3GPP Long TermEvolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that useE-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). cdma2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). “LTE”refers generally to LTE, LTE-Advanced (LTE-A), LTE in an unlicensedspectrum (LTE-whitespace), etc. The techniques described herein may beused for the wireless networks and radio technologies mentioned above aswell as other wireless networks and radio technologies. For clarity,while aspects may be described herein using terminology commonlyassociated with 3G and/or 4G wireless technologies, aspects of thepresent disclosure can be applied in other generation-basedcommunication systems, such as 5G and later, including NR technologies.

Example Wireless Communications System

FIG. 1 illustrates an example wireless network 100, such as a new radio(NR) or 5G network, in which aspects of the present disclosure may beperformed.

As illustrated in FIG. 1, the wireless network 100 may include a numberof BSs 110 and other network entities. A BS may be a station thatcommunicates with UEs. Each BS 110 may provide communication coveragefor a particular geographic area. In 3GPP, the term “cell” can refer toa coverage area of a Node B and/or a Node B subsystem serving thiscoverage area, depending on the context in which the term is used. In NRsystems, the term “cell” and eNB, Node B, 5G NB, AP, NR BS, NR BS, gNB,or TRP may be interchangeable. In some examples, a cell may notnecessarily be stationary, and the geographic area of the cell may moveaccording to the location of a mobile base station. In some examples,the base stations may be interconnected to one another and/or to one ormore other base stations or network nodes (not shown) in the wirelessnetwork 100 through various types of backhaul interfaces such as adirect physical connection, a virtual network, or the like using anysuitable transport network.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,etc. A frequency may also be referred to as a carrier, a frequencychannel, etc. Each frequency may support a single RAT in a givengeographic area in order to avoid interference between wireless networksof different RATs. In some cases, NR or 5G RAT networks may be deployed.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a Closed Subscriber Group (CSG), UEs for users in the home,etc.). A BS for a macro cell may be referred to as a macro BS. A BS fora pico cell may be referred to as a pico BS. A BS for a femto cell maybe referred to as a femto BS or a home BS. In the example shown in FIG.1, the BSs 110 a, 110 b and 110 c may be macro BSs for the macro cells102 a, 102 b and 102 c, respectively. The BS 110 x may be a pico BS fora pico cell 102 x. The BSs 110 y and 110 z may be femto BS for the femtocells 102 y and 102 z, respectively. A BS may support one or multiple(e.g., three) cells.

The wireless network 100 may also include relay stations. A relaystation is a station that receives a transmission of data and/or otherinformation from an upstream station (e.g., a BS or a UE) and sends atransmission of the data and/or other information to a downstreamstation (e.g., a UE or a BS). A relay station may also be a UE thatrelays transmissions for other UEs. In the example shown in FIG. 1, arelay station 110 r may communicate with the BS 110 a and a UE 120 r inorder to facilitate communication between the BS 110 a and the UE 120 r.A relay station may also be referred to as a relay BS, a relay, etc.

The wireless network 100 may be a heterogeneous network that includesBSs of different types, e.g., macro BS, pico BS, femto BS, relays, etc.These different types of BSs may have different transmit power levels,different coverage areas, and different impact on interference in thewireless network 100. For example, macro BS may have a high transmitpower level (e.g., 20 Watts) whereas pico BS, femto BS, and relays mayhave a lower transmit power level (e.g., 1 Watt).

The wireless network 100 may support synchronous or asynchronousoperation. For synchronous operation, the BSs may have similar frametiming, and transmissions from different BSs may be approximatelyaligned in time. For asynchronous operation, the BSs may have differentframe timing, and transmissions from different BSs may not be aligned intime. The techniques described herein may be used for both synchronousand asynchronous operation.

A network controller 130 may be coupled to a set of BSs and providecoordination and control for these BSs. The network controller 130 maycommunicate with the BSs 110 via a backhaul. The BSs 110 may alsocommunicate with one another, e.g., directly or indirectly via wirelessor wireline backhaul.

The UEs 120 (e.g., 120 x, 120 y, etc.) may be dispersed throughout thewireless network 100, and each UE may be stationary or mobile. A UE mayalso be referred to as a mobile station, a terminal, an access terminal,a subscriber unit, a station, a Customer Premises Equipment (CPE), acellular phone, a smart phone, a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, a medical device or medical equipment, a healthcare device, abiometric sensor/device, a wearable device such as a smart watch, smartclothing, smart glasses, virtual reality goggles, a smart wrist band,smart jewelry (e.g., a smart ring, a smart bracelet, etc.), anentertainment device (e.g., a music device, a video device, a satelliteradio, etc.), a vehicular component or sensor, a smart meter/sensor, arobot, a drone, industrial manufacturing equipment, a positioning device(e.g., GPS, Beidou, terrestrial), or any other suitable device that isconfigured to communicate via a wireless or wired medium. Some UEs maybe considered machine-type communication (MTC) devices or evolved MTC(eMTC) devices, which may include remote devices that may communicatewith a base station, another remote device, or some other entity.Machine type communications (MTC) may refer to communication involvingat least one remote device on at least one end of the communication andmay include forms of data communication which involve one or moreentities that do not necessarily need human interaction. MTC UEs mayinclude UEs that are capable of MTC communications with MTC serversand/or other MTC devices through Public Land Mobile Networks (PLMN), forexample. MTC and eMTC UEs include, for example, robots, drones, remotedevices, sensors, meters, monitors, cameras, location tags, etc., thatmay communicate with a BS, another device (e.g., remote device), or someother entity. A wireless node may provide, for example, connectivity foror to a network (e.g., a wide area network such as Internet or acellular network) via a wired or wireless communication link. MTC UEs,as well as other UEs, may be implemented as Internet-of-Things (IoT)devices, e.g., narrowband IoT (NB-IoT) devices.

In FIG. 1, a solid line with double arrows indicates desiredtransmissions between a UE and a serving BS, which is a BS designated toserve the UE on the downlink and/or uplink. A dashed line with doublearrows indicates interfering transmissions between a UE and a BS.

Certain wireless networks (e.g., LTE) utilize orthogonal frequencydivision multiplexing (OFDM) on the downlink and single-carrierfrequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDMpartition the system bandwidth into multiple (K) orthogonal subcarriers,which are also commonly referred to as tones, bins, etc. Each subcarriermay be modulated with data. In general, modulation symbols are sent inthe frequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, the spacing of the subcarriers may be 15 kHz and the minimumresource allocation (called a ‘resource block’) may be 12 subcarriers(or 180 kHz). Consequently, the nominal FFT size may be equal to 128,256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10 or 20megahertz (MHz), respectively. The system bandwidth may also bepartitioned into subbands. For example, a subband may cover 1.08 MHz(e.g., 6 resource blocks), and there may be 1, 2, 4, 8 or 16 subbandsfor system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communications systems, such as NR. NR may utilizeOFDM with a CP on the uplink and downlink and include support forhalf-duplex operation using time division duplex (TDD). A singlecomponent carrier bandwidth of 100 MHz may be supported. NR resourceblocks may span 12 sub-carriers with a sub-carrier bandwidth of 75 kHzover a 0.1 ms duration. Each radio frame may consist of 2 half frames,each half frame consisting of 5 subframes with a length of 10 ms.Consequently, each subframe may have a length of 1 ms. Each subframe mayindicate a link direction (e.g., DL or UL) for data transmission and thelink direction for each subframe may be dynamically switched. Eachsubframe may include DL/UL data as well as DL/UL control data. UL and DLsubframes for NR may be as described in more detail below with respectto FIGS. 6 and 7. Beamforming may be supported and beam direction may bedynamically configured. MIMO transmissions with precoding may also besupported. MIMO configurations in the DL may support up to 8 transmitantennas with multi-layer DL transmissions up to 8 streams and up to 2streams per UE. Multi-layer transmissions with up to 2 streams per UEmay be supported. Aggregation of multiple cells may be supported with upto 8 serving cells. Alternatively, NR may support a different airinterface, other than an OFDM-based. NR networks may include entitiessuch CUs and/or DUs.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more subordinateentities. That is, for scheduled communication, subordinate entitiesutilize resources allocated by the scheduling entity. Base stations arenot the only entities that may function as a scheduling entity. That is,in some examples, a UE may function as a scheduling entity, schedulingresources for one or more subordinate entities (e.g., one or more otherUEs). In this example, the UE is functioning as a scheduling entity, andother UEs utilize resources scheduled by the UE for wirelesscommunication. A UE may function as a scheduling entity in apeer-to-peer (P2P) network, and/or in a mesh network. In a mesh networkexample, UEs may optionally communicate directly with one another inaddition to communicating with the scheduling entity.

Thus, in a wireless communication network with a scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As noted above, a RAN may include a CU and DUs. A NR BS (e.g., eNB, 5GNode B, Node B, transmission reception point (TRP), access point (AP))may correspond to one or multiple BSs. NR cells can be configured asaccess cell (ACells) or data only cells (DCells). For example, the RAN(e.g., a central unit or distributed unit) can configure the cells.DCells may be cells used for carrier aggregation or dual connectivity,but not used for initial access, cell selection/reselection, orhandover. In some cases DCells may not transmit synchronizationsignals—in some case cases DCells may transmit SS. NR BSs may transmitdownlink signals to UEs indicating the cell type. Based on the cell typeindication, the UE may communicate with the NR BS. For example, the UEmay determine NR BSs to consider for cell selection, access, handover,and/or measurement based on the indicated cell type.

FIG. 2 illustrates an example logical architecture of a distributedradio access network (RAN) 200, which may be implemented in the wirelesscommunication system illustrated in FIG. 1. A 5G access node 206 mayinclude an access node controller (ANC) 202. The ANC may be a centralunit (CU) of the distributed RAN 200. The backhaul interface to the nextgeneration core network (NG-CN) 204 may terminate at the ANC. Thebackhaul interface to neighboring next generation access nodes (NG-ANs)may terminate at the ANC. The ANC may include one or more TRPs 208(which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs,gNBs, or some other term). As described above, a TRP may be usedinterchangeably with “cell.”

The TRPs 208 may be a DU. The TRPs may be connected to one ANC (ANC 202)or more than one ANC (not illustrated). For example, for RAN sharing,radio as a service (RaaS), and service specific AND deployments, the TRPmay be connected to more than one ANC. A TRP may include one or moreantenna ports. The TRPs may be configured to individually (e.g., dynamicselection) or jointly (e.g., joint transmission) serve traffic to a UE.

The local architecture 200 may be used to illustrate fronthauldefinition. The architecture may be defined that support fronthaulingsolutions across different deployment types. For example, thearchitecture may be based on transmit network capabilities (e.g.,bandwidth, latency, and/or jitter).

The architecture may share features and/or components with LTE.According to aspects, the next generation AN (NG-AN) 210 may supportdual connectivity with NR. The NG-AN may share a common fronthaul forLTE and NR.

The architecture may enable cooperation between and among TRPs 208. Forexample, cooperation may be preset within a TRP and/or across TRPs viathe ANC 202. According to aspects, no inter-TRP interface may beneeded/present.

According to aspects, a dynamic configuration of split logical functionsmay be present within the architecture 200. As will be described in moredetail with reference to FIG. 5, the Radio Resource Control (RRC) layer,Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC)layer, Medium Access Control (MAC) layer, and a Physical (PHY) layersmay be adaptably placed at the DU or CU (e.g., TRP or ANC,respectively). According to certain aspects, a BS may include a centralunit (CU) (e.g., ANC 202) and/or one or more distributed units (e.g.,one or more TRPs 208).

FIG. 3 illustrates an example physical architecture of a distributed RAN300, according to aspects of the present disclosure. A centralized corenetwork unit (C-CU) 302 may host core network functions. The C-CU may becentrally deployed. C-CU functionality may be offloaded (e.g., toadvanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 304 may host one or more ANC functions.Optionally, the C-RU may host core network functions locally. The C-RUmay have distributed deployment. The C-RU may be closer to the networkedge.

A DU 306 may host one or more TRPs (edge node (EN), an edge unit (EU), aradio head (RH), a smart radio head (SRH), or the like). The DU may belocated at edges of the network with radio frequency (RF) functionality.

FIG. 4 illustrates example components of the BS 110 and UE 120illustrated in FIG. 1, which may be used to implement aspects of thepresent disclosure. As described above, the BS may include a TRP. One ormore components of the BS 110 and UE 120 may be used to practice aspectsof the present disclosure. For example, antennas 452, Tx/Rx 222,processors 466, 458, 464, and/or controller/processor 480 of the UE 120and/or antennas 434, processors 460, 420, 438, and/orcontroller/processor 440 of the BS 110 may be used to perform theoperations described herein and illustrated with reference to FIG. 13.

FIG. 4 shows a block diagram of a design of a BS 110 and a UE 120, whichmay be one of the BSs and one of the UEs in FIG. 1. For a restrictedassociation scenario, the base station 110 may be the macro BS 110 c inFIG. 1, and the UE 120 may be the UE 120 y. The base station 110 mayalso be a base station of some other type. The base station 110 may beequipped with antennas 434 a through 434 t, and the UE 120 may beequipped with antennas 452 a through 452 r.

At the base station 110, a transmit processor 420 may receive data froma data source 412 and control information from a controller/processor440. The control information may be for the Physical Broadcast Channel(PBCH), Physical Control Format Indicator Channel (PCFICH), PhysicalHybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel(PDCCH), etc. The data may be for the Physical Downlink Shared Channel(PDSCH), etc. The processor 420 may process (e.g., encode and symbolmap) the data and control information to obtain data symbols and controlsymbols, respectively. The processor 420 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 430 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) 432 a through 432t. For example, the TX MIMO processor 430 may perform certain aspectsdescribed herein for RS multiplexing. Each modulator 432 may process arespective output symbol stream (e.g., for OFDM, etc.) to obtain anoutput sample stream. Each modulator 432 may further process (e.g.,convert to analog, amplify, filter, and upconvert) the output samplestream to obtain a downlink signal. Downlink signals from modulators 432a through 432 t may be transmitted via the antennas 434 a through 434 t,respectively.

At the UE 120, the antennas 452 a through 452 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) 454 a through 454 r, respectively. Eachdemodulator 454 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 454 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 456 may obtainreceived symbols from all the demodulators 454 a through 454 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. For example, MIMO detector 456 may provide detected RStransmitted using techniques described herein. A receive processor 458may process (e.g., demodulate, deinterleave, and decode) the detectedsymbols, provide decoded data for the UE 120 to a data sink 460, andprovide decoded control information to a controller/processor 480.According to one or more cases, CoMP aspects can include providing theantennas, as well as some Tx/Rx functionalities, such that they residein distributed units. For example, some Tx/Rx processing can be done inthe central unit, while other processing can be done at the distributedunits. For example, in accordance with one or more aspects as shown inthe diagram, the BS mod/demod 432 may be in the distributed units.

On the uplink, at the UE 120, a transmit processor 464 may receive andprocess data (e.g., for the Physical Uplink Shared Channel (PUSCH)) froma data source 462 and control information (e.g., for the Physical UplinkControl Channel (PUCCH) from the controller/processor 480. The transmitprocessor 464 may also generate reference symbols for a referencesignal. The symbols from the transmit processor 464 may be precoded by aTX MIMO processor 466 if applicable, further processed by thedemodulators 454 a through 454 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 110. At the BS 110, the uplink signalsfrom the UE 120 may be received by the antennas 434, processed by themodulators 432, detected by a MIMO detector 436 if applicable, andfurther processed by a receive processor 438 to obtain decoded data andcontrol information sent by the UE 120. The receive processor 438 mayprovide the decoded data to a data sink 439 and the decoded controlinformation to the controller/processor 440.

The controllers/processors 440 and 480 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 440 and/orother processors and modules at the base station 110 may perform ordirect the processes for the techniques described herein. The processor480 and/or other processors and modules at the UE 120 may also performor direct processes for the techniques described herein. The memories442 and 482 may store data and program codes for the BS 110 and the UE120, respectively. A scheduler 444 may schedule UEs for datatransmission on the downlink and/or uplink.

FIG. 5 illustrates a diagram 500 showing examples for implementing acommunications protocol stack, according to aspects of the presentdisclosure. The illustrated communications protocol stacks may beimplemented by devices operating in a in a 5G system (e.g., a systemthat supports uplink-based mobility). Diagram 500 illustrates acommunications protocol stack including a Radio Resource Control (RRC)layer 510, a Packet Data Convergence Protocol (PDCP) layer 515, a RadioLink Control (RLC) layer 520, a Medium Access Control (MAC) layer 525,and a Physical (PHY) layer 530. In various examples the layers of aprotocol stack may be implemented as separate modules of software,portions of a processor or ASIC, portions of non-collocated devicesconnected by a communications link, or various combinations thereof.Collocated and non-collocated implementations may be used, for example,in a protocol stack for a network access device (e.g., ANs, CUs, and/orDUs) or a UE.

A first option 505-a shows a split implementation of a protocol stack,in which implementation of the protocol stack is split between acentralized network access device (e.g., an ANC 202 in FIG. 2) anddistributed network access device (e.g., DU 208 in FIG. 2). In the firstoption 505-a, an RRC layer 510 and a PDCP layer 515 may be implementedby the central unit, and an RLC layer 520, a MAC layer 525, and a PHYlayer 530 may be implemented by the DU. In various examples the CU andthe DU may be collocated or non-collocated. The first option 505-a maybe useful in a macro cell, micro cell, or pico cell deployment.

A second option 505-b shows a unified implementation of a protocolstack, in which the protocol stack is implemented in a single networkaccess device (e.g., access node (AN), new radio base station (NR BS), anew radio Node-B (NR NB), a network node (NN), or the like.). In thesecond option, the RRC layer 510, the PDCP layer 515, the RLC layer 520,the MAC layer 525, and the PHY layer 530 may each be implemented by theAN. The second option 505-b may be useful in a femto cell deployment.

Regardless of whether a network access device implements part or all ofa protocol stack, a UE may implement an entire protocol stack (e.g., theRRC layer 510, the PDCP layer 515, the RLC layer 520, the MAC layer 525,and the PHY layer 530).

FIG. 6 is a diagram 600 showing an example of a DL-centric subframe. Asubframe may comprise a number of slots, for example, one or more DLslots and/or UL slots. A DL-centric subframe may comprise more DL slotsthan UL slots. The DL-centric subframe, as shown in FIG. 6, may includea control portion 602. The control portion 602 may exist in the initialor beginning portion of the DL-centric subframe. The control portion 602may include various scheduling information and/or control informationcorresponding to various portions of the DL-centric subframe. In someconfigurations, the control portion 602 may be a physical DL controlchannel (PDCCH), as indicated in FIG. 6. The DL-centric subframe mayalso include a DL data portion 604. The DL data portion 604 maysometimes be referred to as the payload of the DL-centric subframe. TheDL data portion 604 may include the communication resources utilized tocommunicate DL data from the scheduling entity (e.g., UE or BS) to thesubordinate entity (e.g., UE). In some configurations, the DL dataportion 604 may be a physical DL shared channel (PDSCH).

The DL-centric subframe may also include a common UL portion 606. Thecommon UL portion 606 may sometimes be referred to as an UL burst, acommon UL burst, and/or various other suitable terms. The common ULportion 606 may include feedback information corresponding to variousother portions of the DL-centric subframe. For example, the common ULportion 606 may include feedback information corresponding to thecontrol portion 602. Non-limiting examples of feedback information mayinclude an ACK signal, a NACK signal, a HARQ indicator, and/or variousother suitable types of information. The common UL portion 606 mayinclude additional or alternative information, such as informationpertaining to random access channel (RACH) procedures, schedulingrequests (SRs), and various other suitable types of information. Asillustrated in FIG. 6, the end of the DL data portion 604 may beseparated in time from the beginning of the common UL portion 606. Thistime separation may sometimes be referred to as a gap, a guard period, aguard interval, and/or various other suitable terms. This separationprovides time for the switch-over from DL communication (e.g., receptionoperation by the subordinate entity (e.g., UE)) to UL communication(e.g., transmission by the subordinate entity (e.g., UE)). One ofordinary skill in the art will understand that the foregoing is merelyone example of a DL-centric subframe and alternative structures havingsimilar features may exist without necessarily deviating from theaspects described herein.

FIG. 7 is a diagram 700 showing an example of an UL-centric subframe. Asnoted above, a subframe may comprise a number of slots including one ormore DL slots and/or UL slots. A UL-centric subframe may comprise moreUL slots than DL slots. The UL-centric subframe, a shown in FIG. 7, mayinclude a control portion 702. The control portion 702 may exist in theinitial or beginning portion of the UL-centric subframe. The controlportion 702 in FIG. 7 may be similar to the control portion describedabove with reference to FIG. 6. The UL-centric subframe may also includean UL data portion 704. The UL data portion 704 may sometimes bereferred to as the payload of the UL-centric subframe. The UL portionmay refer to the communication resources utilized to communicate UL datafrom the subordinate entity (e.g., UE) to the scheduling entity (e.g.,UE or BS). In some configurations, the control portion 702 may be aphysical DL control channel (PDCCH).

As illustrated in FIG. 7, the end of the control portion 702 may beseparated in time from the beginning of the UL data portion 704. Thistime separation may sometimes be referred to as a gap, guard period,guard interval, and/or various other suitable terms. This separationprovides time for the switch-over from DL communication (e.g., receptionoperation by the scheduling entity) to UL communication (e.g.,transmission by the scheduling entity). The UL-centric subframe may alsoinclude a common UL portion 706. The common UL portion 706 in FIG. 7 maybe similar to the common UL portion 706 described above with referenceto FIG. 7. The common UL portion 706 may additional or alternativeinclude information pertaining to channel quality indicator (CQI),sounding reference signals (SRSs), and various other suitable types ofinformation. One of ordinary skill in the art will understand that theforegoing is merely one example of an UL-centric subframe andalternative structures having similar features may exist withoutnecessarily deviating from the aspects described herein.

In some circumstances, two or more subordinate entities (e.g., UEs) maycommunicate with each other using sidelink signals. Real-worldapplications of such sidelink communications may include public safety,proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V)communications, Internet of Everything (IoE) communications, IoTcommunications, mission-critical mesh, and/or various other suitableapplications. Generally, a sidelink signal may refer to a signalcommunicated from one subordinate entity (e.g., UE1) to anothersubordinate entity (e.g., UE2) without relaying that communicationthrough the scheduling entity (e.g., UE or BS), even though thescheduling entity may be utilized for scheduling and/or controlpurposes. In some examples, the sidelink signals may be communicatedusing a licensed spectrum (unlike wireless local area networks, whichtypically use an unlicensed spectrum).

A UE may operate in various radio resource configurations, including aconfiguration associated with transmitting pilots using a dedicated setof resources (e.g., a radio resource control (RRC) dedicated state,etc.) or a configuration associated with transmitting pilots using acommon set of resources (e.g., an RRC common state, etc.). Whenoperating in the RRC dedicated state, the UE may select a dedicated setof resources for transmitting a pilot signal to a network. Whenoperating in the RRC common state, the UE may select a common set ofresources for transmitting a pilot signal to the network. In eithercase, a pilot signal transmitted by the UE may be received by one ormore network access devices, such as an AN, or a DU, or portionsthereof. Each receiving network access device may be configured toreceive and measure pilot signals transmitted on the common set ofresources, and also receive and measure pilot signals transmitted ondedicated sets of resources allocated to the UEs for which the networkaccess device is a member of a monitoring set of network access devicesfor the UE. One or more of the receiving network access devices, or a CUto which receiving network access device(s) transmit the measurements ofthe pilot signals, may use the measurements to identify serving cellsfor the UEs, or to initiate a change of serving cell for one or more ofthe UEs.

Example Data Transmission in Synchronization Slots

Under 3GPP's 5G wireless communication standards, a structure has beendefined for NR synchronization (synch) signals (NR-SS), also referred toas NR synchronization channels. Under 5G, a set of consecutive OFDMsymbols carrying different types of synch signals (e.g., primarysynchronization signal (PSS), secondary synchronization signal (SSS),time synchronization signal (TSS), PBCH) forms an SS block. In somecases, a set of one or more SS blocks may form an SS burst. In addition,different SS blocks may be transmitted on different beams to achievebeam-sweeping for synch signals, which may be used by a UE to quicklyidentify and acquire a cell. Further, one or more of the channels in anSS block may be used for measurements. Such measurements may be used forvarious purposes such as radio link management (RLM), beam management,etc. For example, a UE may measure the cell quality and report thequality back in the form of a measurement report, which may be used bythe base station for beam management and other purposes.

FIG. 8 illustrates an example transmission timeline 800 ofsynchronization signals for a new radio telecommunications system. A BS,such as BS 110 shown in FIG. 1, may transmit an SS burst 802 during aperiod 806 of Y μsec, in accordance with certain aspects of the presentdisclosure. Operations 800 begin, at 802, by transmitting asynchronization signal (SS) burst. The SS burst may include N SS blocks804 with indices of zero to N−1, and the BS may transmit different SSblocks of the burst using different transmit beams (e.g., forbeam-sweeping). Each SS block may include, for example, a primarysynchronization signal (PSS), a secondary synchronization signal (SSS),and one or more physical broadcast channels (PBCHs), also referred to assynchronization channels. The BS may transmit SS bursts on a periodicbasis, with a period 808 of X msec.

FIG. 9 illustrates an example resource mapping 900 for an exemplary SSblock 902. The exemplary SS block may be transmitted by a BS, such as BS110 in FIG. 1, over a period 904 (e.g., Y μsec, as shown in FIG. 8). Theexemplary SS block includes a PSS 910, an SSS 912, and two PBCHs 920 and922, although the disclosure is not so limited, and an SS block mayinclude more or fewer synchronization signals and synchronizationchannels. As illustrated, a transmission bandwidth (B1) of the PBCHs maybe different from a transmission bandwidth (B2) of the synchronizationsignals. For example, the transmission bandwidth of the PBCHs may be 288tones, while the transmission bandwidth of the PSS and SSS may be 127tones.

Example of New Radio Synchronization Configuration in DifferentOperation Modes

In accordance with one or more aspects of embodiments described herein,methods and apparatus for synchronization configuration in differentoperation modes using communications systems operating according to newradio (NR) technologies are provided.

Although NR defines a common design for synchronization signals(PSS/SSS) and synchronization channel (PBCH) for all operation modes,different values of synchronization periodicity (SS burst setperiodicity) are proposed for different modes. Further, there are avariety of different synchronization modes such as an initialacquisition in standalone mode, an initial acquisition in non-standalonemode, and synchronization in an idle mode or a connected mode. Anexample of a periodicity value for an initial acquisition in standalonemode may be 20 msec. According to other examples, for either an idlemode, a connected mode, and/or a non-standalone initial acquisition modea variety of different time values may be used such as, for example, 5msec, 10 msec, 20 msec, 40 msec, 80 msec, or 160 msec. Therefore, ingeneral the transmission (Tx) configuration of synchronization indifferent modes may be different.

Thus, in accordance with one or more cases, a Tx configuration of one ormore of the synchronization reference signals and synchronizationchannels (for example, a physical broadcast channel (PBCH)) may bedetermined based on an operation mode. According to one or more cases,the Tx configuration may refer to many different features such as aresource configuration, a sweeping pattern, and/or a signal design.Further, in accordance with one or more aspects, idle/connectedsynchronization transmissions may occur on a set of time-frequencyresources different from those used for initial acquisitionsynchronization transmission. According to one or more cases, the Txconfiguration may be signaled to the UE thru the use of different means.

FIG. 10 illustrates operations 1000 for wireless communications by abase station (BS), in accordance with aspects of the present disclosure.Specifically, operations 1000 begin, at block 1002, with determining anoperation mode of the BS. The operations 1000 further include, at block1004, determining a transmission configuration of at least one of a oneor more synchronization channels or a one or more synchronizationsignals based on the operation mode. Additionally, operations 1000include, at block 1006, transmitting the one or more synchronizationchannels or the one or more synchronization signals based on thedetermined transmission configuration. In some cases, operations 100 mayfurther include signaling the transmission configuration to a userequipment (UE) through one or more of a master information block (MIB),a system information block (SIB), and a radio resource control (RRC)signaling

According to one or more cases, determining the operation mode may bebased on one or more of an indication received from an upper layersignaling; an indication received from the network; a preconfiguredschedule; an indication received from one or more other BSs; anindication received from one or more UEs; and a measurement of the oneor more signals received from one or more UEs.

In accordance with one or more aspects, the one or more synchronizationchannels may include one or more physical broadcast channels (PBCH). Theone or more synchronization signals may include at least one of aprimary synchronization signal (PSS), a secondary synchronization signal(SSS), a third synchronization signal (TSS) carrying SS-block timingindex information, a demodulation reference signal (DMRS) for physicalbroadcast channel (PBCH), or a beam reference signal. The operation modemay include providing synchronization for at least one of an initialacquisition in standalone mode, an initial acquisition in non-standalonemode, one or more UEs in an idle mode, or one or more UEs in a connectedmode.

Further, the transmission configuration may include configuration of oneor more of: at least one of a time resource or a frequency resource usedfor the transmission of the one or more synchronization channels or theone or more synchronization signals; at least one of a digital precodingor an analog precoding used for transmitting at least one of the one ormore synchronization channels or the one or more synchronization signalsfrom one or more antenna ports; a number of antenna ports used fortransmission of at least one of the one or more synchronization channelsor the one or more synchronization signals; a composition of at leastone of a synchronization signal (SS) block, an SS burst, or an SS burstset; a beam sweeping pattern; or a waveform design of the one or moresynchronization signals. The waveform design may include at least one ofa TSS or a DMRS for at least one of a PBCH or a beam reference.

In some cases, the operation mode may be signaled to a user equipment(UE) through the one or more synchronization channels or the one or moresynchronization signals. Additional operations may be included such assignaling, within a broadcast channel (BCH) transmission time interval(TTI), a location of a synchronization signal (SS) block consisting ofat least one of the one or more synchronization channels or the one ormore synchronization signals to the UE. Further, the signaling may beprovided through the one or more synchronization channels or the one ormore synchronization signals.

In one or more cases, transmitting the one or more synchronizationchannels or the one or more synchronization signals based on thedetermined transmission configuration may include transmitting the oneor more synchronization channels or the one or more synchronizationsignals on a first set of time-frequency resources when transmitting inat least one of an initial acquisition in standalone mode or an initialacquisition in non-standalone mode. Additionally, transmitting the oneor more synchronization channels or the one or more synchronizationsignals on a second set of time-frequency resources different from thefirst set of time-frequency resources when transmitting in at least oneof an idle mode or connected mode may be included. According to one ormore cases, the first set of time-frequency resources may include adifferent frequency band for transmission than the second set oftime-frequency resources. In another example, the first set oftime-frequency resources may include a synchronization raster. In one ormore cases, the first set of time-frequency resources may include thesame frequency band as the second set of time-frequency resources. Inaccordance with some cases, the first set of time-frequency resourcesmay include different time locations as compared to the second set oftime-frequency resources.

In accordance with one or more cases, transmitting the one or moresynchronization channels or the one or more synchronization signalsbased on the determined transmission configuration may includetransmitting, to a select group of UEs in a discontinuous reception(DRX) operation mode, the one or more synchronization channels or theone or more synchronization signals on a set of DRX time-frequencyresources. The DRX time-frequency resources may include one or more of anon-raster location and time domain resources different from initialacquisition time domain resources. Further, the one or moresynchronization channels or the one or more synchronization signals maybe transmitted before a DRX ON cycle to the select group of UEs.

FIG. 11 illustrates example operations for wireless communications by auser equipment (UE), in accordance with aspects of the presentdisclosure. Specifically, operations 1100 begin, at block 1102, withdetermining a transmission configuration, used by a base station (BS),to transmit at least one of a one or more synchronization channels or aone or more synchronization signals based on an operation mode. Theoperations 1100 may further include, at block 1004, configuring the UEto communicate based on the transmission configuration.

According to some cases, additional operations may be included such asreceiving an indication of the operation mode of the BS through the oneor more synchronization channels or the one or more synchronizationsignals. Further, configuring the UE to communicate may be further basedon the determined operation mode of the BS. According to one or morecases, the operation mode of the BS may include providingsynchronization for at least one of an initial acquisition in standalonemode, an initial acquisition in non-standalone mode, one or more UEs inan idle mode, or one or more UEs in a connected mode.

Further, another operation that may be included is receiving anindication of a location of a synchronization signal (SS) blockconsisting of at least one of the one or more synchronization channelsor the one or more synchronization signals, within a broadcast channel(BCH) transmission time interval (TTI). The indication may be providedthrough the one or more synchronization channels or the one or moresynchronization signals. The operations may further include determiningthe operation mode of the BS based, at least in part, on the location ofthe SS block, and configuring the UE to communicate based further on thedetermined operation mode of the BS. The operation mode of the BS mayinclude providing synchronization for at least one of an initialacquisition in standalone mode, an initial acquisition in non-standalonemode, one or more UEs in an idle mode, or one or more UEs in a connectedmode.

Additional features and details for one or more embodiments may bedescribed as follows. According to one or more cases, transmissionconfiguration of a synchronization reference signals and/orsynchronization channel (PBCH) may be determined based on an operationmode. The synchronization reference signals may be a PSS, a SSS, a TSS(carrying SS block timing index info), and/or a DMRS for PBCH or a beamreference signal. The operation mode may refer to one or more of aninitial acquisition (in standalone or non-standalone) mode, an idlemode, or a connected mode.

The Tx configuration may include or reference any one or combination ofdifferent features. Some of these features may include: time and/orfrequency resources used for the transmission of the synchronizationreference signals (and channel); digital and/or analog precoding forbeam-forming used for the transmission from each antenna port; a numberof antenna ports used for the transmission of the synchronizationreference signals and/or synchronization channel; and a composition ofSS block, SS burst, and/or SS burst set. Another feature that may beincluded in the Tx configuration includes a beam sweeping pattern. Thebeam sweeping pattern may include how frequently an SS is transmittedtowards different directions. Further, the Tx configuration for includea waveform design of the reference signals. For example, Txconfiguration may include a TSS and/or DMRS for PBCH and/or beamreference.

According to one or more cases, one example may include anidle/connected synchronization transmission which may occur on a set oftime-frequency resources different from those used for initialacquisition synchronization transmission In accordance with one or morecases, an idle/connected synchronization transmission may be provided ona different frequency band from an initial acquisition synchronizationtransmission which may be transmitted using another frequency band.Particularly, in accordance with one or more cases, a specificapplication may include a scenario where an initial acquisitionsynchronization may be transmitted on a synchronization raster in thefrequency domain. In contrast, the idle/connected mode synchronizationmay or may not be transmitted on a synchronization raster.

In accordance with one or more cases, transmissions may also be providedduring a discontinuous reception (DRX) operation mode. in some cases,synchronization transmission may occur in a non-raster location, in thefrequency domain (FD) while, in the time domain (TD), some resources maybe used that are not necessarily aligned with TD resources of theinitial acquisition synchronization. Synchronization may be transmittedright before a DRX ON cycle for a group of UEs. In this example, suchsynchronization may be used as a warm-up signal in this case, similar toa CSI-RS. Further, the Tx configuration may include transmissionperiodicity of SS blocks and possibly a reduced set of SS blockscompared to the initial acquisition.

The Tx configuration for synchronization may be signaled to a UE thruone or any combination of an MIB, SIB, or RRC signaling, any one or moreof which may be preconfigured in accordance with one or more cases. Insome cases, the Tx configuration for synchronization in idle/connectedmode or non-standalone mode may be signaled to a UE thru one or anycombination of a MIB, SIB, or RRC signaling over LTE, in the case ofLTE+NR dual connectivity being provided. According to another example,the MIB, SIB, RRC signaling may be provided over a first NR system, in acase where the first NR system and a second NR system are togetherproviding dual connectivity. The first and second NR systems may operateat different carrier frequencies. For example, the first NR system mayoperate at a sub-6 GHz and the second NR system may operate on mmWave.

FIG. 12 illustrates an example of synchronization transmissions, inaccordance with aspects of the present disclosure. As shown, SS blocksfor both ideal and connected mode are transmitted in pairs at an initialtime, at 20 msec, and at 80 msec as shown. Additionally, SS blocks forconnected mode are transmitted as a pair starting at 10 msec. after theinitial time. Accordingly, as shown the transmission of both sets ofblocks do no overlap in time showing different time resource usage.Further, one or more of the SS block transmissions may also betransmitted using a different frequency from that used for one or moreof the other SS block transmissions.

In accordance with one or more cases, an idle/connected synchronizationtransmission may occur on a set of time-frequency resources differentfrom those used for initial acquisition sync transmission. In somecases, SS blocks may convey whether one or more of the SS blocks areintended for idle/connected SYNC. According to another example, SSblocks may convey the exact location of SS block inside the BCHtransmission time interval (TTI); instead of just mentioning the SSblock index in the SS burst set or the SS burst set index inside the BCHTTI. In accordance with one or more cases, one or more combinations ofPSS, SSS, TSS, and PBCH may convey the information in either of theabove examples.

In accordance with one or more cases, while a UE is in a first operationmode such as, for example, a mode for synchronization for initialaccess, the UE may receive a SS block transmitted by the BS intended foranother second operation mode. For example, the BS may transmit an SSblock for a group of UEs in an RRC-idle or an RRC-connected mode.

Further, in accordance with one or more examples, the UE may determinean operation mode of the BS and the received SS block throughsynchronization signals and/or channels. According to another case, theUE may determine an operation mode of the BS and the received SS blockbased on the determined location of the SS block within the BCH TTI.Further, the UE may determine an operation mode of the BS and thereceived SS block through a combination of the synchronization signalsand/or channels and the determined location of the SS block within theBCH TTI.

According to one or more cases, a UE's processing and communication withBS may be based on a determined intended operation mode of BS of thereceived SS block(s). According to some cases, if the UE wants to dosome measurements using the received SS block(s), these measurements maydepend on the determined operation mode of BS of each SS block.According to other cases, if the UE wants to transmit RACH preamble tothe BS based on the received SS block(s), the configuration (resourcesand waveform) of the RACH transmission may depend on the determinedoperation mode of BS of each RXed SS block.

In accordance with one or more aspects, an operation mode may refer toan initial acquisition in standalone mode of one or more UEs or aninitial acquisition in standalone mode of one or more BSs. Further, insome cases, an operation mode may refer to an initial acquisition innon-standalone mode of one or more UEs or an initial acquisition innon-standalone mode of one or more BSs. According to some aspects,synchronization, beam management, and/or mobility management of UEs orBSs may be provided when in an idle/connected mode.

In one or more cases, the determination of the operation mode mayadditionally be based on a capability of one or more of the UEs and/orBSs that a BS is communicating with. One or more of the capabilities mayinclude RF and digital processing capabilities, beam correspondence,power, etc.

In accordance with one or more aspects, a configuration may additionallyrefer to a subcarrier spacing (SCS) and/or a cyclic prefix (CP) size ofsignals and/or channels. The configuration may further refer to physicalbroadcast channel (PBCH) content and a coding configuration used togenerate the PBCH from the content. Further, the configuration may referto SS block composition, which may refer to the number and order ofsymbols carrying the synchronization signal and/or channels. Forexample, a number of PBCH symbols within block 4, 5, or 6 may bereferenced. In some cases a configuration may additionally refer to anSS burst set composition, which may include the number and resources ofthe transmitted (TXed) SS blocks within a burst set. A configuration mayalso refer to the transmit (TX) power setting of the synchronizationsignals and/or channels. For example, the TX power offset betweendifferent synchronization signals and/or channels may be referenced.More specifically, the TX power offset between DMRS and PBCH tones, orbetween SSS and DMRS tones, may be referenced.

In some cases, an indication coming from another cell with the same ordifferent RAT may be provided. For example, such an indication may beprovided by a serving cell for a neighbor cell. There are some caseswhere the configuration may be specific to a UE, a BS, a group of UEs,or a group of BSs

The methods described herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c). Asused herein, including in the claims, the term “and/or,” when used in alist of two or more items, means that any one of the listed items can beemployed by itself or any combination of two or more of the listed itemscan be employed. For example, if a composition is described ascontaining components A, B, and/or C, the composition can contain Aalone; B alone; C alone; A and B in combination; A and C in combination;B and C in combination; or A, B, and C in combination.

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” For example, the articles “a” and“an” as used in this application and the appended claims shouldgenerally be construed to mean “one or more” unless specified otherwiseor clear from the context to be directed to a singular form. Unlessspecifically stated otherwise, the term “some” refers to one or more.Moreover, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.” That is, unless specified otherwise or clearfrom the context, the phrase, for example, “X employs A or B” isintended to mean any of the natural inclusive permutations. That is, forexample the phrase “X employs A or B” is satisfied by any of thefollowing instances: X employs A; X employs B; or X employs both A andB. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing described herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed under the provisions of 35 U.S.C. § 112, sixth paragraph,unless the element is expressly recited using the phrase “means for” or,in the case of a method claim, the element is recited using the phrase“step for.”

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components withsimilar numbering.

Means for transmitting and/or means for receiving may comprise one ormore of a transmit processor 420, a TX MIMO processor 430, a receiveprocessor 438, or antenna(s) 434 of the base station 110 and/or thetransmit processor 464, a TX MIMO processor 466, a receive processor458, or antenna(s) 452 of the user equipment 120. Additionally, meansfor determining, means for signaling, means for configuring, and/ormeans for providing may comprise one or more processors, such as thecontroller/processor 440 of the base station 110 and/or thecontroller/processor 480 of the user equipment 120.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a userterminal 120 (see FIG. 1); a user interface (e.g., keypad, display,mouse, joystick, etc.) may also be connected to the bus. The bus mayalso link various other circuits such as timing sources, peripherals,voltage regulators, power management circuits, and the like, which arewell known in the art, and therefore, will not be described any further.The processor may be implemented with one or more general-purpose and/orspecial-purpose processors. Examples include microprocessors,microcontrollers, DSP processors, and other circuitry that can executesoftware. Those skilled in the art will recognize how best to implementthe described functionality for the processing system depending on theparticular application and the overall design constraints imposed on theoverall system.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, phasechange memory, ROM (Read Only Memory), PROM (Programmable Read-OnlyMemory), EPROM (Erasable Programmable Read-Only Memory), EEPROM(Electrically Erasable Programmable Read-Only Memory), registers,magnetic disks, optical disks, hard drives, or any other suitablestorage medium, or any combination thereof. The machine-readable mediamay be embodied in a computer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein. For example, instructions for performing the operationsdescribed herein and illustrated in the appended figures.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

What is claimed is:
 1. A method for wireless communications by awireless node comprising: determining an operation mode of the wirelessnode; determining a transmission configuration of at least one of a oneor more synchronization channels or a one or more synchronizationsignals based on the operation mode; and transmitting the one or moresynchronization channels or the one or more synchronization signalsbased on the determined transmission configuration.
 2. The method ofclaim 1, wherein determining the operation mode is based on one or moreof: an indication received from an upper layer signaling; an indicationreceived from a network; a preconfigured schedule; an indicationreceived from one or more BSs; an indication received from one or moreUEs; and a measurement of the one or more signals received from one ormore UEs.
 3. The method of claim 1, wherein: the one or moresynchronization channels comprise one or more physical broadcastchannels (PBCH), and the one or more synchronization signals comprise atleast one of a primary synchronization signal (PSS), a secondarysynchronization signal (SSS), a third synchronization signal (TSS)carrying SS-block timing index information, a demodulation referencesignal (DMRS) for physical broadcast channel (PBCH), or a beam referencesignal.
 4. The method of claim 1, wherein the operation mode comprises:providing one or more of synchronization, beam management, and mobilitymanagement for at least one of an initial acquisition in standalone modeof UEs or BSs, an initial acquisition in non-standalone mode of UEs orBSs, one or more UEs or BSs in an idle mode, or one or more UEs or BSsin a connected mode.
 5. The method of claim 1, wherein: the transmissionconfiguration includes configuration of one or more of: at least one ofa time resource or a frequency resource used for the transmission of theone or more synchronization channels or the one or more synchronizationsignals; at least one of a digital precoding or an analog precoding usedfor transmitting at least one of the one or more synchronizationchannels or the one or more synchronization signals from one or moreantenna ports; a number of antenna ports used for transmission of atleast one of the one or more synchronization channels or the one or moresynchronization signals; a composition of at least one of asynchronization signal (SS) block, an SS burst, or an SS burst set; abeam sweeping pattern; or a waveform design of the one or moresynchronization signals; the transmission configuration refers to one ormore of: a subcarrier spacing (SCS) and a cyclic prefix (CP) size ofsignals or channels, physical broadcast channel (PBCH) content and acoding configuration, an SS block composition that refers to a numberand order of symbols carrying the one or more synchronization signals orone or more synchronization channels, an SS burst set composition, or atransmit power setting of the one or more signals or one or moresynchronization channels; and the transmission configuration is specificto at least one of the UE, the BS, a group of UEs, or a group of BSs. 6.The method of claim 1, further comprising: signaling the operation modeto a user equipment (UE) through the one or more synchronizationchannels or the one or more synchronization signals.
 7. The method ofclaim 1, further comprising: signaling to a user equipment (UE) alocation of a synchronization signal (SS) block consisting of at leastone of the one or more synchronization channels or the one or moresynchronization signals, within a broadcast channel (BCH) transmissiontime interval (TTI).
 8. The method of claim 1, wherein transmitting theone or more synchronization channels or the one or more synchronizationsignals based on the determined transmission configuration comprises:transmitting the one or more synchronization channels or the one or moresynchronization signals on a first set of time-frequency resources whentransmitting in at least one of an initial acquisition in standalonemode or an initial acquisition in non-standalone mode; and transmittingthe one or more synchronization channels or the one or moresynchronization signals on a second set of time-frequency resourcesdifferent from the first set of time-frequency resources whentransmitting in at least one of an idle mode or connected mode.
 9. Themethod of claim 8, wherein: the first set of time-frequency resourcesincludes a different frequency band for transmission than the second setof time-frequency resources, and the first set of time-frequencyresources includes a synchronization raster.
 10. The method of claim 8,wherein: the first set of time-frequency resources includes the samefrequency band as the second set of time-frequency resources, and thefirst set of time-frequency resources includes different time locationsas compared to the second set of time-frequency resources.
 11. Themethod of claim 1, wherein transmitting the one or more synchronizationchannels or the one or more synchronization signals based on thedetermined transmission configuration comprises: transmitting, in adiscontinuous reception (DRX) operation mode, the one or moresynchronization channels or the one or more synchronization signals on aset of DRX time-frequency resources, wherein the DRX time-frequencyresources include one or more of a non-raster location and time domainresources different from initial acquisition time domain resources, andwherein the one or more synchronization channels or the one or moresynchronization signals are transmitted before a DRX ON cycle to aselect group of UEs, or a group of BSs.
 12. The method of claim 1,further comprising: signaling the transmission configuration to a userequipment (UE) through one or more of a master information block (MIB),a system information block (SIB), and a radio resource control (RRC)signaling.
 13. The method of claim 1, further comprising: signaling thetransmission configuration to a user equipment (UE) through one or moreof an MIB, an SIB, and an RRC signaling over a first system, whereindual connectivity is provided between the first system and a secondsystem, wherein the first system is at least one of an LTE system or afirst NR system and the second system is a second NR system, wherein thefirst and second systems operate at different carrier frequencies,wherein the first NR system operates at a sub-6 GHz carrier frequency,and the second NR system operates at an mmWave carrier frequency, andwherein the operation mode comprises at least one of an initialacquisition in non-standalone mode, an idle mode, or a connected mode.14. A method for wireless communications by a wireless node comprising:determining a transmission configuration, used by a base station (BS),to transmit at least one of a one or more synchronization channels or aone or more synchronization signals based on an operation mode; andconfiguring the wireless node to communicate based on the transmissionconfiguration.
 15. The method of claim 14, wherein determining thetransmission configuration comprises: receiving an indication of thetransmission configuration from at least one of the BS or another BSthrough at least one of a MIB, a SIB, or a RRC signaling.
 16. The methodof claim 14, wherein the operation mode is determined by the UE based onone or more of: an indication received from an upper layer signaling; anindication received from a network; a preconfigured schedule; anindication received from one or more BSs; an indication received fromone or more other UEs; and a measurement of the one or more signalsreceived from one or more BSs.
 17. The method of claim 14, wherein: theone or more synchronization channels comprise one or more physicalbroadcast channels (PBCH), and the one or more synchronization signalscomprise at least one of a primary synchronization signal (PSS), asecondary synchronization signal (SSS), a third synchronization signal(TSS) carrying SS-block timing index information, a demodulationreference signal (DMRS) for physical broadcast channel (PBCH), or a beamreference signal.
 18. The method of claim 14, wherein the operation modecomprises one or more of synchronization, beam management, and mobilitymanagement for at least one of an initial acquisition in standalone modeof UEs or BSs, an initial acquisition in non-standalone mode of UEs orBSs, an idle mode of UEs or BSs, or a connected mode of UEs or BSs. 19.The method of claim 14, wherein: the transmission configuration includesconfiguration of one or more of: at least one of a time resource or afrequency resource used for the transmission of the one or moresynchronization channels or the one or more synchronization signals; atleast one of a digital precoding or an analog precoding used fortransmitting at least one of the one or more synchronization channels orthe one or more synchronization signals from one or more antenna ports;a number of antenna ports used for transmission of at least one of theone or more synchronization channels or the one or more synchronizationsignals; a composition of at least one of a synchronization signal (SS)block, an SS burst, or an SS burst set; a beam sweeping pattern; or awaveform design of the one or more synchronization signals; and thetransmission configuration refers to one or more of: a subcarrierspacing (SCS) and a cyclic prefix (CP) size of signals or channels,physical broadcast channel (PBCH) content and a coding configuration, anSS block composition that refers to a number and order of symbolscarrying the one or more synchronization signals or one or moresynchronization channels, an SS burst set composition, or a transmitpower setting of the one or more signals or one or more synchronizationchannels; and the transmission configuration is specific to at least oneof the UE, the BS, a group of UEs, or a group of BSs.
 20. The method ofclaim 14, further comprising: receiving the one or more synchronizationchannels or the one or more synchronization signals on a first set oftime-frequency resources when the UE is in a first operation mode; andreceiving the one or more synchronization channels or the one or moresynchronization signals on a second set of time-frequency resourcesdifferent from the first set of time-frequency resources when the UE isin a second operation mode.
 21. The method of claim 20, wherein: thefirst set of time-frequency resources includes a different frequencyband than the second set of time-frequency resources, and the first setof time-frequency resources includes a synchronization raster.
 22. Themethod of claim 20, wherein: the first set of time-frequency resourcesincludes the same frequency band as the second set of time-frequencyresources, and the first set of time-frequency resources includesdifferent time locations as compared to the second set of time-frequencyresources.
 23. The method of claim 14, further comprising: receiving, ina discontinuous reception (DRX) operation mode, the one or moresynchronization channels or the one or more synchronization signals on aset of DRX time-frequency resources, wherein the DRX time-frequencyresources include one or more of a non-raster location and time domainresources different from initial acquisition time domain resources, andwherein the one or more synchronization channels or the one or moresynchronization signals are transmitted before a DRX ON cycle to the UE.24. The method of claim 14, further comprising: receiving an indicationof the operation mode of the BS through the one or more synchronizationchannels or the one or more synchronization signals, wherein configuringthe UE to communicate is further based on the determined operation modeof the BS, and wherein the operation mode of the BS comprises: providingsynchronization for at least one of an initial acquisition in standalonemode, an initial acquisition in non-standalone mode, one or more UEs inan idle mode, or one or more UEs in a connected mode.
 25. The method ofclaim 14, further comprising: receiving an indication of a location of asynchronization signal (SS) block consisting of at least one of the oneor more synchronization channels or the one or more synchronizationsignals, within a broadcast channel (BCH) transmission time interval(TTI), wherein the indication is through the one or more synchronizationchannels or the one or more synchronization signals; determining theoperation mode of the BS based, at least in part, on the location of theSS block; and configuring the UE to communicate based further on thedetermined operation mode of the BS.
 26. The method of claim 1, wherein:determining the operation mode is based on a capability of a UE or agroup of UEs or BSs that the UE is part of, and the capability includesone or more of an RF processing capability, a digital processingcapability, a beam correspondence, and a power.
 27. The method of claim1, wherein: determining the operation mode is based on an indicationreceived from another cell with a same or different radio accesstechnology (RAT), and the other cell is a serving cell for a neighborcell.
 28. The method of claim 14, further comprising: determining theoperation mode based on a capability of the UE or a group of UEs or BSsthat the UE is part of, wherein the capability includes one or more ofan RF processing capability, a digital processing capability, a beamcorrespondence, and a power.
 29. The method of claim 14, whereindetermining the transmission configuration comprises: receiving anindication from another cell with a same or different radio accesstechnology (RAT), wherein the another cell is a serving cell for aneighbor cell.
 30. A method for wireless communications by a wirelessnode comprising: determining a transmission configuration, used by abase station (BS), to transmit at least one of a one or moresynchronization channels or a one or more synchronization signals basedon an operation mode; and transmitting the transmission configuration toa user equipment (UE) or another BS for communicating with the BS.